Treehouse of Horror XXVII: Returning, New and leaving items in the store!

A new item has joined the store: the House on Scary Hill; a new bundle has joined too: THOH Flashback Bundle #3 with the following items (also available separate if you’ve one of them already): Bad Dream House, The Raven, Springfield Cemetery; while the last 24 hours for Spooky Wall are here!

That could be cool… But are the 1hr zombie jobs limited in how many can use it at one time (like the Nightmare Pile or Bounce House), or can multiple/all the townsfolk listed above do the task concurrently (like Duff Gardens)?